Lens grinding and polishing machine.



I. J. LANDE.

LENS GRINDING AND POLISHING MACHINE.

APPLICATIO N FILED JAN- 26, I914.

on V W M m P Y J b WW a? 3 l t 3 E 8 L aflv f 0 1 E ma, 1 .ll 1

I. J; LANDE. LENS GRINDING AND POLISHING MACHINE.

Patented Oct'17', 1916.

2 SHEETS-SHEET 2 APPLICATION HLED JAN- 26, 1914.

WINNIE-- WWNEEEJE: 'llf a ATTU NEY:

rsanoan a. m nor, or BUFFALO, NEW YORK.

LENS GRINDING AND POLISHING MACHINE.

assists.

Specification of was Patent,- t t (mt, 17,' 191 Application filedJanuary 26, 1914. Serial No. 814,353.

To all whom itmay concern 'I Be it known that I,- Isabonn J. LANDE, a

citizen of the United States, residing at Buffalo, inthe county of Erieand State of New 'York," have invented new and useful Improvements in usGrinding and Polishf ing, Machines, of which the followingis a- 4 ispecification; vention relates to a machine for and polishing toric andother lenseshavmg compound curvatures.-

In machines as ordinarily constructed, a

lens-holder or chuck. is employed in connection? with a i15fgrinding'padhaving its face previously curvatiues, entailing considerable expense.

ground or shaped to the desired curvature of" the leis. This'arrangementrequires the useof separate pads for different radii or jMoreover, ifthe pad contains imperfections .ie'r wears unevenly, which is often thecase,

F -One of the as;

thejcurve' impartedto the lens is incorrect sirinaccurate.

objects of myinvention is the production of a grin chine arias characterwhich the correct 1| dingof the lenses is not dependent on the erfectionofihe grinm'ng pad or the accur'ate curvatnrcf'f its grinding face, butwhich accurate predetermined curvature or.

is-"soorgan'med that it. will grind lenses to radius regardless ofimperfections of the grinding pad and without the necessity of .arnplonumerous pads with different eurvatures, thus efiecting an importantsav- 4 mg A further object is the construction of a simple machine ofthis kind which can be f readily adjusted to grind toric lenses to.

curves of different radii as required.

Another object is to improve the "con 1 is a sectional side elevation ofthe machine showing the parts in the same position.

Fig. 3 1s "asectional top plan view thereof. Fig; i is a fragmentaryfront QlGVtltlOllQf the machine showing the grinding pad in position tod convex lenses. Fig. is a .face'view of'the lens-holder or'chuck. Figs.

relatively-stationary ding and'polishmg ma permit of'this action. Thechuck is 6, 7 and 8 are diagrammatic views illustrat-.

ing different adjustments of the chuck for producing curvatl res ofdifferent radii. Snmlar charac ers of reference indicate correspondingparts throughout the several views.

and 3 is the main driving shaft of the machine journaled horizontally.in the frame.

" Arranged above the table 2 is the rotary work or lens-holder or chuck4 which is preferably'cylindrical, or in the form of a drum, and to thecylindrical rim of which the lens-blanks 5 arc/adapted to be attached bypitch or any other suitable'cement, the blanks being cemented either tothe inner or the outer side of the rim to produce concave or convexlenses. In some cases the lens-blanks may be cemented directly to therim of the chuck, but in grinding concavelenses a number ofinterchangeable lens-carrying rings of different thicknesses lindicates-the upright frame of a ma chine on which is mounted a bedor-table 2,

are preferably employed, one of which is shown in the drawings anddesignated 6 This ring may be removably secured in the chuck by anysuitable means.

In the'construction shown, the chuck is cast in one piece, and its rimis split or di- -vided transversely at diametrically-opp0- site sides,as shown at 7 the split portions thereof being connected by clampingbolts 8, so that by tightening or loosenin 'these boltsthe lens-carryingring 6 is c amped therein or'released. The" split the chuck-rim? havesufficient e asticit to ortions of to the front end of a horizontalshaft 9 journaled in a bearing 10 carried by a slide or carriage 11which is mounted to slide transversely of said shaft on a standard 12.The latter rises from a horizontally-swinging or oscillatory arm 13arranged above the table 2 and fixed to the upper end of an upright rockshaft 14 which turns in suitable bearings on the table 2 .and the frame1, and extends through and below said table. This shaft is actuated byany suitable .means, the preferred means consisting of a rock arm 15secured to its lower end and having a pin 16 which engages. a

grooved rotary cam 17 mounted loosely on the main shaft 3. A suitableclutch 18 serves to throw this cam into and out ofgear with said mainshaft which'is adapted The chuck carriage 11 may be adjusted.

on the standard of the oscillating arm 13 by a horizontal screw 22, suchas commonly used for adjusting lathe stocks, or by any othersuitablemeans. The carriage is also provided with a set screw 23 forretaining it in position. Rotary motion is imparted from the main shaft3 to the chuck by a sprocket chain 24 passing around sprocket wheels 25and 26 secured to the chuck-shaft 9 and the hub of the cam 17. Thischain may be provided with a suitableibelt tightener27. 1

Referring to the concave grinding machine shown in Figs. 1, 2 and 3,28indicates' the grinding pad mounted in a suitable holder 29 swiveled bya horizontal pivot 30 to 'the end of a horizontal arm or bracket 31.This bracket extends into the hollow chuck and has a shank 32' arrangedat right angles to the axis of the chuck and clamped to the horizontalhead of a support or standard 33 by a bolt 34 passing through alongitudinal slot 35 of said shank. By

this construction, upon loosening the clamping bolt 34, the pad can beadjusted toward or from the inner face of the chuck-rim toaccommodatethe same to lens-cariwing rings 6 of different thicknesses. To preventthe bracket 31 from swinging laterally on the bolt 34, a pair ofclampingscrews 34 bear against opposite edges of the slotted shank, asshown in Fig. 3, these screws being arranged in perforated lugs carriedby the standard 33.

The pad-supporting standard 33 is pivoted at its lower end to abase-plate or car-' riage 36 by a pin 37 normally arranged parallel withthe axis of the rotary chuck 4, so that said standard may swing at rightangles to said axis to permit the grinding pad to approach and recedefrom the inner face of the chuck-rim. Bearing against the rear side ofthis standard isa pressure-arm 38 also pivoted at its lower end to thebaseplate 36 bya pin 39 arranged parallel with the pin 37 and preferablycarrying an antifriction roller 40 which bears against a boss 41 of thestandard 33. This arm carries an overhanging weight 42 whereby aconstant pressureis exerted against the standard 33 which in turnpresses the grinding pad against the lenses of the chuck,- in a mannercommon to this class of machines. The forward movement of the standard33 is liniited by a suitable stop which preferably .consists of a screw43 hearing against the This base plate may be clamped in position by avertical screw or bolt 46 journaled in the table 2 and having a handle.47, said plate being provided in its front edge with a notch 48 whichreceives said screw, as shown by dotted lines in Fig. 3. Other suitablemeans may however be employed for this purpose. If desired, the hub ofthe base-plate may be provided with an additional clamping screw 49which engages the pivot pin 45.

In'addition to the pad-support or standard 33, the machine is preferablyprovided with a supplemental standard 50, of substantially the sameconstruction, arranged to face the outer side of the cylindricalchuck-rim, as best shown in Figs. 1 and 4, to support and hold agrinding pad 28 for grinding convex lenses. In this case, thepad-bracket 51 is slotted like the bracket 31 and adjustably secured tothe top of the standard 50, as in the first described support byclamping bolts 52 and 53, but as the pad is applied to the outer side ofthe chuck, the bracket is straight and arranged radially of the chuck.The standard is pivoted .to swing toward and from the chuck, itslowerend being hinged by a pin 54 to a fixed base 55 mounted on the table 2.

Like the first-described pad support, this supplemental support 50 has apressure arm 56 carrying an overhanging weight 57 and an adjustable stop5-8.

The operation of the machine is iias follows: l/Vhen lenses are to beground concave, the lens-blanks are cemented to the inner face of alens-carrying .ring6 of the required thickness to produce a verticalcurvature of the prescribed radius. drawing the grinding pad from thechuck, said ring is, inserted in the chuck and clamped therein bytightening the bolts 8, after which the grinding pad is returned to itsnormal position within the chuck, these movements of the pad beingeffected by swinging the carriage or base plate 36 away from or towardthe chuck, as hereinbefore described. Upon now setting the machine inmotion, the chuck 4 is constantly rotated on its axis and at the sametime bodily oscillated by the rocking movement of the shaft 14 producedby the rotary cam 17. The chuck is thus oscillated on an axis arrangedAfter withsubstantially at right angles to its own axis of rotation,with the result that-this oscillating motion of the chuck in ahorizontal plane relatively to the stationary "grinding pad causes thelenses to be ground to th desired horizontal curvature, while therotarymotion of the chuck causes them to be ground to the desired verticalcurvature. Obviously, the chuck oscillates in a predetermined arc withreference to the face of the grinding pad and the radius of thehorizontal curve to which the lens is groimd therefore remains constantand accurate,

2 even if the pad has an imperfect surface or develops imperfections bywear. 7

Variations in the radius of the vertical curve of the lenses areobtained by changing the distance between the axis of the chuck and-theface of the lenses.

6- of different thicknesses, as

This may be done by using separate lens-carrying rings, hereinbeforedescribed, but if desired, the pitch bed in a the lenses are obtained bylengthening or shortening the radius of which the len'sesare seated maybe thinned or thickened for this purpose.

Variations in the horizontal curvature of oscillation of the chuck, orin otherjwords, varying the distance between the axis of the rock shaft14 and the inner face of the chuck-rim, which is accomplished by,shifting the chuck 4' laterally on the standard 12 of the oscillatingarm 13 by means of the carriageadjustin screw 2-2, the pad-bracket 31being1 adjuste accordingly. This action'will be c early understood byreferenceto Figs. 6, 7 and 8, where the dotted vertical line A indicatesthe axis of oscillation of the chuck and the distance or radius fromdotted line B the said axis to the concave faces of thelenses. In Fig.6.the axis of rotation of the chuck is coincident with its axis 'A'ofoscillation,

' circular To increase or diminish and in this adjustment the verticaland horizontal curves of the lenses are ground to the same radius,producing spherical lenses.

horizontal curvature of the lenses for producing toric lenses, the chuckis shifted laterally to either side of the central position shown inFig. 6, the chuck being shifted toward the right from said central positon to increase said radius, as shown in Fig. andtoward the left fromsaid central position to shorten said radius, as shown in Flg. 8.In-either case, this. adjustment can be readily and accurately effectedby means of Convex;

the carriage-adjusting screw 22. spherical and toric lenses can belikewise ground and polished by chine as shown-in Fig. 4.

' It is a characteristic tion that the lens-blanks are applied to the vcylindrical chuck wall or rim of the or lens-holder 4 and that theiatter has two motions with reference'to the relatively-star.-

the radius of they carriage and coiiperating with adjusting themafeature of my inven chlne,'.the combination of a relatively-staalentmotion about its axis and an oscillatory motion on an axis substantiallyat right angles to its axis of IOttfllOIl. By this comparatively simple"expedient or compound motion of the chuck, the machine is caused togrind both curvatures of toric or other compound lenses with the utmostaccuracy, regardless-of the shape of the face of-the grinding pad orinequalities-of its texture or other imperfections. At the same time,this construction efi'ects an important sav-' ing, in that it avoids thenecessity of employing a plurality or variety of grinding pads, eachhaving a grinding face of predetermined and previously-ground contour,as in ordinary lens-grinding machines in which one of the two curvaturesof toric or other compound-lenses is produced by the curve.- ture of thegrinding-padand therefore depends for its correctness upon the accuracyof the face of the pad and the maintenance of such accuracy throughoutthe grinding. operation of the lens.

I claim as my invention:

1. In a lens-grinding or polishing machine,.the combination of acylindrical lensholder adapted to carry the lens-blanks on itscylindrical wall, said holder having a its axis of oscillation beingsubstantially at right angles to its axis of rotation, means foractuating the holder, and a relatively-stationary grinding pad havingits grinding" surface arranged to face the cylindrical wall of thelens-holder.

2. In a'lens grinding or polishing machine, the combination of arelatively-sta-' tionary grinding pad, a rotary cylindrical cillation toincrease or diminish the radius of the lens-curve produced by suchoscillatory motion, and means for actuating the lens-holder. I

3. In a lens-grinding or polishing machine, the combination of arelatively-stationary grinding pad, an oscillatory memher, a carriageadjustable on said member in a plane transversely of its axis ofoscillation, a rotary lens-holder mounted on said said pad, saidlens-holder having its axis arranged substan-v tially at right angles tosaid axis of oscillation, and means for actuating said member. and thelens-holder.

4. In a lens-grinding or polishing mationary grinding pad, a rock shaftcarrying an arm. a carriage adjustable on said arm in a planetransversely of its axis of oscillacompound rotary and oscillatorymotion and tion, a rotary lens-holder mounted on said carriage andcoperating with said pad, and means for actuating said rock shaft andthe lens-holder. a

5 5. In a lens-grinding or polishing 11121- chine, the combination of arelatively-stationary grinding pad, a rock shaft carrying an arm, a camfor actuating said shaft to 05;-

illate said arm, arotary 1ens-h0lder mount- 10 ed on said arm with itsaxis substantially at right angles to the axis of said rock shaft, andmeans for actuating said shaftand the lens-holder.

Witness my hand this 24th day of January, 1914C.

ISADORE J. LANDE.

Witnesses:

LOUIS SGHULMAN, C. F. GEYER.

